Electrically controlled pressure equalizing apparatus



ELECTRICALLY "CONTROLLED PRESSURE EQUALIZINGAPPARATUS I 21, 1936 G. T. DQNCEEL Filed June 28, 1935 2 Sheets-Sheet 1 W 1936- G. T. DONCEEL ELEGTRICALLY CONTROLLED PRESSURE EQUALIZING APPARATUS Filed June 28, 1955 2 Sheets-Sheet 2 a w w J as? if 37 Patented Apr. 21, 1936 UNITED STATES PATENT OFFICE ELECTRICALLY CONTROLLED PRESSURE EQUALIZING APPARATUS Guillaume Thomas Donc'eel, Oklahoma City, Okla.

Application June 28, 1933, Serial No. 678,097 4 Claims. 2236-15) ments of the lever for operation of electrical de vices controlling the action of draft apparatus.

It is a further object of the invention to provide control apparatus for a draft device that may be directly operated by pneumatic, hydraulic or other means and wherein opposed forces, such as suction and draft are associated with the control apparatus.

With the above and other objects in view that will become apparent as the-nature of the invention is better understood. the sameconsists in the novel form, combination and arrangement of parts hereinafter more fully described, shown in the accompanying drawings and claimed.

In the drawings:-

Figure 1 is a side elevational View, partly broken 25 away and shown in section of the electrically controlled pressure equalizing apparatus showing the lever having the air draft and fuel pressure operated devices associated therewith at one side of the lever fulcrum and the switch at the opposite 30 side of the fulcrum;

Figure 2 is a top plan view of the apparatus showing the adjustable mounting for the fuel pressure controlled device;

' Figure 3 is a side elevational View, partly broken away and shown in section of the diaphragm cas ing in communication with the fuel supply system;

Figure 4 is a detail plan view of the mercury switches and supporting shaft therefor to be op- 40 erated by a pressure operated lever together with the motor operated segment for operating the flue damper and further showing the cut-out switches for the motor rendered operable at extreme movement of the damper.

4 The electrically controlled pressure equalizing apparatus while adapted for various uses will be described as associated with the draft operated type of gas burner for furnaces. The apparatus includes a lever ID to be pivotally mounted in prox- 5 imity of one end thereof as at H, the end pivot I providing relatively short and long arms l2 and I3. The draft flue of the furnace is in communication with the free end of the lever arm |3 by means of a gasometer-like construction l4 including an annular casing of receptacle formation having a bottom wall I5 and an annular side wall It. The casing includes an inner concentric annular wall |1 providing a chamber l8 open at its upper end. A tapering funnel-like wall I 9 extends from the upper edge of the inner annular 5 I wall I1 and terminates centrally of the bottom wall |5 in a reduced spout or pipe section that is in communication with the draft flue'of a furnace. A bell 2| forms a part of the gasometerlike construction I4 and has a depending annular l0 flange 22 depending into the chamber l8 that is filled with liquid as is customary in such devices.

. The upper end of the bell 2| has a flexible cord or cable connection 23 with the free end of the lever arm l3 as at 24. In the presence of in- 15 creased draft through the furnace flue, the bell 2| is drawn downwardly into the casing 4 to elTect. lowering movement of the lever arm' I3, pivotal movements ofthe lever l0 being limited by stop pins 25 at the upper and lower endsof an 2 arm 26 associated with the free end of the lever arm l3.

: The pressure of the gas or liquid fuel supply system of the furnace is in communication with the lever arm l3 and acts to raise the lever arm 25 I3 in opposition 'to a downward pull by the bell 2|, the reference character 21 designating a casing divided by a diaphragm 28 into upper and lower chambers 29 and 30, the lower chamber 30 having a nipple connection 3| for attachment 30 with the conduit supplying pressure from the gas or fuel supply system for the furnace. The casing 21 is adjustably supported above the gasometer-like casing I4 bymeans of bearings 32 carried by the upper side thereof and slidable on horizontally disposed guide rods 33. The adjustment of the casing 21 is in a direction lengthwise of the lever arm l3 and is accomplished by means of the lever 34 pivotally mounted as at 35 to swing in a horizontal direction, one end thereof having a pin and slot connection 36 with the upper side of the casing 21 while the other end thereof has a pin and slot strap connection 31 with a nut 38 threaded on a screw 39 swivelled as at 4|] so that upon rotation of the screw 39 the casing 21 is shifted on the guide rod 33 to be positioned at the desired distance from the lever pivot This adjustable or shifting movement of the casing 21 relative to the lever pivot effects the assigning of the desired ratio between the two pressures exerted on the longer arm I 3 of the lever Hi, the assigned ratio being changeable at will. The connection between the casing 21 and lever arm l3 shows an inverted V-shaped strap 4| rising from the bearings 32. A rod 21a extending downward- 1y through an opening centrally of the top wall of the casing projects through the diaphragm 28 with its lower headed end 215 anchored to the under side of the diaphragm, the upper end of the rod extending upwardly through the V-shaped guide 4| and carrying intermediate its ends a cross pin 42 extending through the longitudinal slot 43 in the lever arm l3. The screw 39 is operated by the knurled head 39a.

Pivotal movement of the lever I is utilized for the operation of two arc shaped mercury tube switches which serve the function of a two-blade double throw switch for reversing the polarity of current supply to an electric motor that effects opening and closing movement of the draft damper of the furnace. A rotatable tubular shaft 44 is rotatably mounted by means of a bearing pin 45 at one end thereof in a plane parallel with and offset from the short arm |2 of the lever l0, its other end being supported in any convenient manner. The end of the tubular shaft 44 adjacent the bearing pin 45 is machined toprovide a pinion 46 engaged by a rack plate 41 extending at right angles from the free end of the short arm I2 of the lever ID, the ratio of the plate gear 41 and pinion 45 being such that a full movement of the plate gear will turn the pinion through approximately 180. A disk plate 48 is secured axially of the tubular shaft 44 substantially midway the ends thereof and carries upon opposite faces tubular arcuate mercury switches 49 and 50 respectively movable with the disk 48 on the tubular shaft 44 for moving a small quantity of mercury in each tube into position for the closing of switches, for controlling the direction of rotation of the reversible electric motor The reversible motor 5| is employed for the operation of the flue damper 52 for controlling the feed of air or draft through the flue of the furnace by means of the toothed sector 53 having the toothed portion 54 thereof engaged with the worm 53 driven by means of the shaft of the motor 5| through themedium of gear reduction mechanism 56. The flue damper 52 and the toothed sector 53 are mounted on the shaft 5311 which constitutes a pivot therefor. The reversible motor 5| is placed in communication with a source of potential by the mercury tubes 49 and. 50 and a pair of cut-out switches is set into the circuit wiring to be engaged by the toothed sector for bringing the motor 5| to rest and to stop movement of the damper 52 when moved to its fully open or closed position. The two throwout switches include respectively as shown in Figure 4, terminals 58--58a and 59-5911. The switch arms 6|! and 6| carried by the terminals 58 and 58a are engageable with the terminals 59 and 59a and include overhanging portions 600. and 6|a respectively engageable by the outer ends 5101. and 51b of the side portions of the toothed sector 53 for breaking the circuit to the reversible motor 5| when the damper 52 has reached its fully open or closed position. The wiring arrangement for the mercury tube switches, throwout switches and motor is briefly illustrated in Figure 4 and is of a character to: effect rotation of the motor for the opening and closing movements of the damper 52 as well as bringing the damper to rest when in fully opened or closed position, the wire a from the motor 5|, extending to and branching at the point I) in the tubular shaft 44, one branch 0 extending for engagement with the contact d in the mercury tube switch Eli and the other branch e extending for engagement with the contact 1 in the mercury tube switch 49. According to the positions of the switches the wire 9 receives the electric current from either the wire h or the wire k, resulting in a change of polarity of the current in the wire g to correspond with the change of polarity in the wire a, the change in polarity resulting from the direction of throw of the mercury switch. The wire g from the motor 5| extends to the switch terminal 58a; and from the switch terminal 58a the wire h extends to terminal 59 and through the switch blade 99 to the terminal 59 and as the wire i to the contact 7' in the mercury tube switch 49; and from the switch terminal 58a the switch blade 5| extends to terminal 590., and the wire is from the throw-out switch terminal 59a leads to the contact m in the mercury tube switch 59. The wires n and o in communication with a source of potential respectively lead to the contacts 12 in the mercury tube switch 59 and the contacts q in the mercury tube switch 49.

Communication is established between the tube section 20 of the gasometer-like casing and the combustion chamber of a furnace and communication is established between the fuel supply system registering pressure in the diaphragm casing 21 in a manner to allow gas pressure to act upon the lower side of the diaphragm 28. With the feeding of gas or other fuel for the operation of the furnace, pressure thereof acts upon the diaphragm in the casing 21 to raise the rod 21a to move the lever l9 upon its pivot II as shown in Figure 2 for rotating the tubular shaft 44 tomove the mercury tube switch through an arc of approximately 90, resulting in the closing of the circuit which operates the motor in the direction to open the damper 52. As the damper opens, the increased draft exerts an increased pull upon the bell of the gasometer and when the draft reaches the proper amount assigned for efiicient combustion, the lever 13 is lowered to its normal'position to accomplish the equalizing or balancing of the upward forceexerted by the gas pressure with the mercury switches breaking the circuit to the motor 5|. With a reduction in the amount of gas or other fuel fed to the furnace, the reduced pressure thereof under the diaphragm 28 in the diaphragm casing 21 allows the pull of the draft at the underside of the bell 2| of the gasometer-like casing Hi to overcome the gas pressure in the diaphragm casing 21 lowering the lever I3 and causing a reverse closing of the mercury tube switches 49and 59, for the reverse operation of the motor 5| resulting in the closing of the damper until the draft diminishes sufficiently to allow the'lever ID to balance. When the upwardly exerted pressure on the lever I0 ceases, the. damper is closed, the draft being reduced to a minimum for the conservation of heat. Extreme movements of the damper 52 is controlled by the toothed sector 53 having the ends 51a and 51b respectively engaged with the overhanging portions 69a and Bla of the throw-out switch blades 69 and 6| respectively for cutting off the supply of current to the motor 5| when the mercury tube switches are closed. The automatic regulation, equalization or balancing of the fuel and air supply to the furnace is accomplished by this apparatus in which fuel and draft pressure operate upon a lever at one side of the fulcrum thereof. The parts of the apparatus are so related as to counterbalance so that the weight of any part will not appreciably retard or 'aid the oppositely acting forces.

While there is herein shown and. described the preferred embodiment of the invention, it is nevertheless to be understood that minor changes may be made therein without departing from the spirit and scope of the invention as claimed.

I claim:-

1. Electrically controlled pressure equalizing apparatus including a pivoted lever, suction and pressure operated devices exerting forces in opposite directions on the lever at one side of the lever fulcrum for balancing the lever, the pressure operated device including a diaphragm operated rod, a lateral pin carried thereby, the lever having an elongated slot therein receiving the pin and a screw device for shifting the pressure operated device longitudinally of the slotted end of the lever for varying the relationship of the opposing forces acting on the lever.

2. In operating mechanism for a furnace damper, a suction device adapted for communication with the combustion chamber of a furnace, a pressure operated device adapted for communication with the fuel supply for the furnace, a fulcrumed lever, said suction and pressure operated devices exerting forces in opposite directions on thelever at one side of the fulcrum, a flue damper for the furnace, operating means for the damper and means for rendering the damper operating means inoperative when the damper is in fully opened or closed position for stopping the motor, and the pressure operated device including a diaphragm operated rod, a lateral pin carried thereby, the lever having an elongated slot therein receiving the pin and means for shifting the pressure operated device the lever.

3. In operating mechanism for a furnace damper, a suction device adapted for communication with the combustion chamber of a furnace, a pressure operated device adapted for communication with the pressure medium effecting supply of fuel to the furnace, a fulcrumed lever, said suction and pressure operated devices exerting forces in opposite directions on the lever at one side of the fulcrum, the suction operated device being connected to the outer end of the lever and the pressure operated device connected to the lever inwardly of its outer end and adjustable longitudinally of the lever, a furnace damper and operating means for the damper interposed between the damper and inner end of the lever.

4. In operating mechanism for a furnace damper, a suction device adapted for communication with the combustion chamber of a furnace, a pressure operated device adapted for communication with the pressure medium effecting supply of fuel to the furnace, a fulcrumed lever,

said suction and pressure operated devices exerting forces in opposite directions on the lever at one side of the fulcrum the suction operated device being connected to the outer end of the lever and the pressure operated device connected to the lever inwardly of its outer end and adjustable longitudinally of the lever, and movable means controlled in its operation by said lever.

GU'ILLAUME THOMAS DONCEEL. 

